The instant invention relates to optically active uracil compounds and uses thereof.
U.S. Pat. No. 4,859,229 discloses that certain types of uracil compounds have herbicidal activity. However, there is no description concerning whether the herbicidal activities between the optical isomers are the same or different, or which optical isomer is more effective as a herbicidal active ingredient.
Generally speaking, in pesticides field, it is known that some optically active isomers have almost the same activity as their racemic compounds and the other optically active isomers have at most twice activity than their racemic compounds. It seems to be dependent on a structure near the asymmetric carbon in the compound whether the pesticidal activity between the optical isomers is the same or different. However, it is very difficult to estimate a pesticidal activity of an optical isomer without experimentation. When one optical isomer is almost inactive, the other optical isomer is theoretically considered to be effective twice against its racemate, because the racemate contains a half amount of the active optical isomer.
The present invention provides optically active uracil compounds having excellent herbicidal activity. Said uracil compounds are of the formula (I): 
wherein, R1 is C1-C8 alkyl or C3-C8 alkenyl, and * represents an asymmetric carbon atom whose configuration is R, and have excellent herbicidal activity.
The present uracil compounds may be essentially pure R isomer in the 2nd position of the propionate, namely essentially free from S isomer, or R-rich isomers of the absolute configuration in the 2nd position of the propionate, shown in the above formula [hereinafter referred to as the present compound(s)]. In the present invention, essentially pure R isomer means one containing 95% or more R isomer, and R-rich isomer generally means one containing 80% or more R isomer based on the RS mixture.
In the present invention, examples of the C1-C8 alkyl represented by R1 include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, amyl, isoamyl, sec-amyl, tert-amyl and hexyl, and examples of the C3-C8 alkenyl represented by R1 include allyl, 1-methyl-2-propenyl, 3-butenyl, 2-butenyl, 3-methyl-2-butenyl and 2-methyl-3-butenyl. Among the present compounds, the compounds wherein R1 is C1-C6 alkyl or C3-C6 alkenyl are preferable.
The present compounds can be produced by methods, for example, shown in the following.
(Production Method 1)
A method of production by reacting a hydroxy compound of the formula (II): 
with an S-lactate of the formula (III): 
wherein R1 represents the same as defined above.
Said reaction is usually performed in the presence of a triarylphosphine or trialkylphosphine such as triphenylphosphine, triethylphosphine, tributylphosphine and the like, in combination with a di(lower alkyl) azodicarboxylate such as diethyl azodicarboxylate, diisopropyl azodicarboxylate, and the like. Said reaction is usually performed within a solvent, and the range of the reaction temperature is usually xe2x88x9220 to 150xc2x0 C., preferably 0 to 100xc2x0 C., and the range of the reaction time is instantaneous to 48 hours. The amount of the S-lactate of the formula (III) used in the reaction is generally 1 to 3 moles, preferably 1 to 1.2 moles, based on 1 mole of the hydroxy compound of the formula (II). The amount of the triarylphosphine or trialkylphosphine is generally 1 to 3 moles, preferably 1 to 1.2 moles, and the amount of the di(lower alkyl) azodicarboxylate is generally 1 to 3 moles, preferably 1 to 1.2 moles, based on 1 mole of the hydroxy compound of the formula (II). Examples of the solvent utilized for the reaction include aliphatic hydrocarbons such as hexane, heptane, ligroin, cyclohexane and petroleum ether; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and benzotrifluoride; ethers such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether; and the like, and mixtures thereof. After completing the reaction, for example, by the methods shown below, the objective present compounds can be isolated.
1) The reaction solution is poured into water, that is extracted with an organic solvent, said organic layer is dried and concentrated, and the residue is subjected to chromatography.
2) The reaction solution is concentrated as it is, and the residue is subjected to chromatography.
In addition, it is possible to purify the present compounds by operations such as recrystalization.
The hydroxy compound of the formula (II) can be prepared by the method described in U.S. Pat. No. 4,859,229.
(Production Method 2)
A method of production by reacting a hydroxy compound of the formula (II) with an S-2-chloropropionate of the formula (IV): 
wherein R1 represents the same as defined above.
Said reaction is usually performed in the presence of a base within a solvent, and the range of the reaction temperature is usually xe2x88x9220 to 100xc2x0 C., preferably 0 to 40xc2x0 C., and the range of the reaction time is instantaneous to 240 hours. The amount of the S-2-chloropropionate of the formula (IV) used in the reaction is generally 1 to 2 moles, preferably 1 to 1.2 moles, based on 1 mole of the hydroxy compound of the formula (II). The amount of the base is generally 1 to 3 moles, preferably 1 to 1.2 moles, based on 1 mole of the hydroxy compound of the formula (II). Examples of the base utilized for the reaction include inorganic bases such as lithium carbonate, sodium carbonate, potassium carbonate, sodium hydride and potassium hydride. Examples of the solvent utilized for the reaction include aliphatic hydrocarbons such as hexane, heptane, ligroin, cyclohexane and petroleum ether; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and benzotrifluoride; ethers such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone and cyclohexanone; esters such as ethyl formate, ethyl acetate, butyl acetate and diethyl carbonate; nitriles such as acetonitrile, propionitrile and butyronitrile; acid amides such as formamide, N,N-dimethylformamide and acetamide; sulfur compounds such as dimethyl sulfoxide and sulfolane; and the like, and mixtures thereof. After completing the reaction, for example, by the methods shown below, the objective present compounds can be isolated.
1) The reaction solution is poured into water, that is extracted with an organic solvent, said organic layer is dried and concentrated, and the residue is subjected to chromatography.
2) The reaction solution is concentrated as it is, and the residue is subjected to chromatography.
(Production Method 3)
A method of producing from a carboxylic acid compound of the formula (V): 
and an alcohol compound of the formula (VI):
R1OH
wherein R1 represents the same as defined above.
(Production Method 3-1)
A method of producing by reacting a carboxylic acid compound of the formula (V) with an alcohol compound of the formula (VI) directly.
Said reaction is usually performed in the presence of an acid, without or within a solvent, and the range of the reaction temperature is usually from 20 to 150xc2x0 C., preferably 50 to 100xc2x0 C., and the range of the reaction time is usually from instantaneous to 24 hours. The amount of the alcohol compound of the formula (VI) used in the reaction is generally 1 mole to a large excess and the amount of the acid is generally a catalytic amount to 1 mole based on 1 mole of the carboxylic acid compound of the formula (V). Examples of the acid utilized for the reaction include inorganic acid such as sulfuric acid; sulfonic acid such as methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid; ion-exchange resin that is acidic cation resin; and the like. Examples of the solvent utilized for the reaction include aliphatic hydrocarbons such as hexane, heptane, nonane, decane, ligroin, cyclohexane and petroleum ether; halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane and 1,2,3-trichloropropane; aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and benzotrifluoride; ethers such as diethyl ether, diisopropyl ether, methyl tert-butyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether; and the like, and mixtures thereof. After completing the reaction, for example, by the methods shown below, the objective present compounds can be isolated.
1) The reaction solution is poured into water optionally after concentrated, that is extracted with an organic solvent, said organic layer is dried and concentrated, and the residue is subjected to chromatography.
2) The reaction solution is concentrated as it is, and the residue is subjected to chromatography.
The carboxylic acid compound of the formula (V) can be prepared by hydrolysis of the uracil compounds of the formula (I). Therefore, this method serves an ester exchange procedure, and especially it is suitable for the process from methyl or ethyl ester to the other esters.
The hydrolysis may be performed in the presence of an acid and water, and usually within a solvent. The range of the reaction temperature is usually from 20 to 150xc2x0 C., preferably 70 to 110xc2x0 C., and the range of the reaction time is usually from instantaneous to 48 hours. The amounts of the acid used in the reaction is generally a catalytic amount to 1 mole, preferably a catalytic amount to 0.2 mole, based on 1 mole of the uracil compound of the formula (I). The amount of the water is generally 1 mole to a large excess, based on 1 mole of the uracil compound of the formula (I). Examples of the acid utilized for the hydrolysis include inorganic acid such as hydrochloric acid and sulfuric acid; sulfonic acid such as methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid; and the like. Examples of the solvent utilized for the reaction include dioxane, tetrahydrofuran and the like. After completing the reaction, for example, by the methods shown below, the objective compound can be isolated.
1) The reaction solution is poured into water optionally after concentrated, that is extracted with an organic solvent, said organic layer is dried and concentrated, and the residue is subjected to chromatography.
2) The reaction solution is concentrated as it is, and the residue is subjected to chromatography.
This method may be modified by known procedures utilizing a dehydration-esterifying agent such as dicyclohexylcarbodiimide.
(Production Method 3-2)
A method of producing by reacting a reactive intermediate such as acid chloride, which can be derived from a carboxylic acid compound of the formula (V), with an alcohol compound of the formula (VI).
Said method may be performed by, after making such into an acid chloride compound by reacting the carboxylic acid compound of the formula (V) with a chlorinating agent (hereinafter referred to as procedure 3-2-1), reacting with the alcohol compound of the formula (VI), in the presence of a base (hereinafter referred to as procedure 3-2-2).
Procedure 3-2-1 is performed without a solvent or within a solvent. The range of the reaction temperature is usually from 0 to 150xc2x0 C., and the range of the reaction time is usually from instantaneous to 24 hours. The amount of the chlorinating agent offered with the reaction is theoretically 1 mole based on 1 mole of the carboxylic acid compound of the formula (V), but optionally the amount may be changed in the range of 1 mole to an excess as needed with the reaction condition. Examples of the chlorinating agent utilized for the reaction include thionyl chloride, sulfuryl chloride, phosgene, oxalyl chloride, phosphorous trichloride, phosphorous pentachloride and phosphorous oxychloride. Examples of the solvent include aliphatic hydrocarbons such as hexane, heptane, nonane, decane, ligroin, cyclohexane and petroleum ether; aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane and 1,2,3-trichloropropane; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and benzotrifluoride; ethers such as diethyl ether, diisopropyl ether, methyl tert-butyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether; and the like, and mixtures thereof. After completing the reaction, the reaction solution is usually concentrated under reduced pressure, and the concentrated residue is utilized as it is for procedure 3-2-2.
Procedure 3-2-2 is performed in the presence of a base, and within a solvent or without a solvent. The range of the reaction temperature is usually xe2x88x9220 to 100xc2x0 C., and the range of the reaction time is usually instantaneous to 24 hours. The amounts of the base and the alcohol compound (VI) used in the reaction are theoretically 1 mole respectively, based on 1 mole of the carboxylic acid compound of the formula (V), but optionally the amounts may be changed in the range of 1 mole to an excess as needed with the reaction condition. Examples of the base utilized for the reaction include inorganic bases such as lithium hydrogencarbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, lithium carbonate, sodium carbonate and potassium carbonate; nitrogen-containing aromatic compounds such as pyridine, quinoline, 4-dimethylaminopyridine, 2-picoline, 3-picoline, 4-picoline, 2,3-lutidine, 2,4-lutidine, 2,5-lutidine, 2,6-lutidine, 3,4-lutidine, 3,5-lutidine, 3-chloropyridine, 2-ethyl-3-methylpyridine and 5-ethyl-2-methylpyridine; tertiary amines such as triethylamine, diisopropylethylamine, tri-n-propylamine, tri-n-butylamine, benzyldimethylamine, phenethyldimethylamine, N-methylmorpholine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]-non-5-ene or 1,4-diazabicyclo[2.2.2]octane. Examples of the solvent include aliphatic hydrocarbons such as hexane, heptane, nonane, decane, ligroin, cyclohexane and petroleum ether; aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane and 1,2,3-trichloropropane; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and benzotrifluoride; ethers such as diethyl ether, diisopropyl ether, methyl tert-butyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether; and the like, and mixtures. After completing the reaction, for example, by the methods shown below, the objective present compounds can be isolated.
1) The reaction solution is poured into water, that is extracted with an organic solvent, said organic layer is dried and concentrated
2) The reaction solution is concentrated as it is, or as needed, is filtered and the filtrate is concentrated. In addition, it is possible to purify the present compounds by operations such as recrystalization and chromatography.
This method may be modified by known procedures utilizing carbonyldiimidazole in place of the chlorinating agent.
The present compounds have excellent herbicidal activity, and some of them exhibit excellent selectivity between crop plants and unfavorable weeds. The present compounds show a herbicidal efficacy in foliar treatment and soil treatment of fields, for example, against the various kinds of problematic weeds mentioned in the following.
Polygonaceae:
wild buckwheat (Polygonum convolvulus), pale smartweed (Polygonum lapathifolium), pennsylvania smartweed (Polygonum pensylvanicum), ladysthumb (Polygonum persicaria), curly dock (Rumex crispus), broadleaf dock (Rumex obtusifolius), Japanese knotweed (Polygonum cuspidatum)
Portulacaceae:
common purslane (Portulaca oleracea)
Caryophyllaceae:
common chickweed (Stellaria media)
Chenopodiaceae:
common lambsquarters (Chenopodium album), kochia (Kochia scoparia)
Amaranthaceae:
redfoot pigweed (Amaranthus retroflexus), smooth pigweed (Amaranthus hybridus)
Crusiferae:
wild radish (Raphanus raphanistrum), wild mustard (Sinapis arvensis), shepherdspurse (Capsella bursapastoris)
Leguminosae:
hemp sesbania (Sesbania exaltata), sicklepod (Cassia obtusifolia), Florida beggarweed (Desmodium tortuosum), white clover (Trifolium repens)
Malvaceae:
velvet leaf (Abutilon theophrasti), prickly sida (Sida spinosa)
Violaceae:
field pansy (Viola rafinesquii), wild pansy (Viola tricolor)
Rubiaceae:
catchweed bedstraw (cleavers) (Galium aparine)
Convolvulaceae:
ivyleaf morningglory (Ipomoea hederacea), tall morningglory (Ipomoea purpurea), entireleaf morningglory (Ipomoea hederacea var intergriuscula), pitted morningglory (Ipomoea lacunosa), field bindweed (Convolvulus arvensis)
Labiatae:
purple deadnettle (Lamium purpureum), henbit (Lamium amplexicaule)
Solanaceae:
jimsonweed (Datura stramonium), black nightshade (Solanum nigrum)
Scrophulariaceae:
persian speedwell (Veronica persica), ivyleaf speedwell (Veronica hederaefolia)
Compositae:
common cocklebur (Xanthium strumarium), common sunflower (Helianthus annuus), scentless chamomile (Matricaria perforata or inodora), corn marigold (Chrysanthemum segetum), pineappleweed (Matricaria matricarioides), common ragweed (Ambrosia artemisiifolia), giant ragweed (Ambrosia trifida), horseweed (Erigeron canadensis), japanese mugwort (Artemisia princeps), tall goldenrod (Solidago altissima)
Boraginaceae:
field forget-me-not (Myosotis arvensis)
Asclepiadaceae:
common milkweed (Asclepias syriaca)
Euphorbiaceae:
sun spurge (Euphorbia helioscopia), spotted spurge (Euphorbia maculata)
Gramineae:
barnyardgrass (Echinochloa crus-galli), green foxtail (Setaria viridis), giant foxtail (Setaria faberi), large crabgrass (Digitaria sanguinalis), goosegrass (Eleusine indica), annual bluegrass (Poa annua), blackgrass (Alopecurus myosuroides), wild oats (Avena fatua), johnsongrass (Sorghum halepense), quackgrass (Elytrigia repens), downy brome (Bromus tectorum), bermudagrass (Cynodon dactylon), fall panicum (Panicum dichotomiflorum), Texas panicum (Panicum texanum), shattercane (Sorghum bicolor)
Commelinaceae:
common dayflower (Commelina communis)
Equisetaceae:
field horsetail (Equisetum arvense)
Cyperaceae:
rice flatsedge (Cyperus iria), purple nutsedge (Cyperus rotundus), yellow nutsedge (Cyperus esculentus)
Additionally, some of the present compounds do not show a problematic phytotoxicity against important crops such as corn (Zea mays), wheat (Triticum aestivum), barley (Hordeum vulgare), rice (Oryza sativa), sorghum (Sorghum vulgare), soybean (Glycine max), cotton (Gossypium spp.), sugar beet (Beta vulgaris), peanut (Arachis hypogaea), sunflower (Helianthus annuus) and canola (Brassica napus); gardening plants such as flowering plants and ornamental plants; vegetable crops.
The present compounds can attain effective control of unfavorable weeds in the no-tillage cultivation of crops such as soybean, corn and wheat. Furthermore, some of them do not show a problematic phytotoxicity against crops.
The present compounds have herbicidal activity against various unfavorable weeds as recited below under the flooding treatment on paddy fields.
Gramineae:
early watergrass (Echinocholoa oryzoides)
Scrophulariaceae:
Common falsepimpernel (Lindernia procumbens)
Lythraceae:
Indian toothcup (Rotala inidica), Ammannia multiflora 
Elatinaceae:
water wort (Elatine triandra)
Cyperaceae:
smallflower umbrellaplant (Cyperus difformis), hardstem bulrush (Scirpus juncoides), needle spikerush (Eleocharis acicularis), water nutgrass (Cyperus serotinus), water chesnut (Eleocharis kuroguwai)
Pontederiaceae:
monochoria (Monochoria vaginalis)
Alismataceae:
arrowhead (Sagittaria pygmaea), Sagittaria trifolia, waterplantain (Alisma canaliculatum)
Potamogetonaceae:
roundleaf pondweed (Potamogeton distincutus)
Umbelliferae:
watercelery (Oenanthe javanica)
Furthermore, some of the present compounds do not show a problematic phytotoxicity against transplanted paddy rice.
The present compounds can attain effective control of various unfavorable weeds in orchards, pastures, lawns, forests, waterways, canals, or other non-cultivated lands.
The present compounds also have herbicidal activity against various aquatic plants such as water hyacinths (Eichornia crassipes) which grow in waterways, canals and the like.
The present compounds have substantially the same characteristics as those of the herbicidal compounds described in the publication of International Patent Application, WO95/34659. In the case where crops with tolerance imparted by introducing a herbicide tolerance gene described in the publication are cultivated, the present compounds can be used at greater doses than those used when ordinary crops without tolerance are cultivated, and it is, therefore, possible to attain effective control of other unfavorable plants.
When the present compounds are used as active ingredients of herbicides, they are usually mixed with solid or liquid carriers or diluents, surfactants, and/or other formulation auxiliary agents, and formulated into such as emulsifiable concentrates, wettable powders, flowables, granules, concentrated emulsions, and water-dispersible granules.
These formulations may contain any of the present compounds as an active ingredient at an amount of 0.001% to 80% by weight, preferably 0.005% to 70% by weight, based on the total weight of the formulation.
Example of the solid carrier or diluent may include fine powders or granules of the following materials: mineral matters such as kaolin clay, attapulgite clay, bentonite, terra abla, pyrophyllite, talc, diatomaceous earth and calcite, organic substances such as walnut shell powder, water soluble organic substances such as urea, inorganic salt such as ammonium sulfate, and synthetic hydrated silicon dioxide. Examples of the liquid carrier or diluent may include the following materials:aromatic hydrocarbons including alkylbenzenes such as methylnaphthalene, phenylxylylethane, and xylene alcohols such as isopropyl alcohol, ethylene glycol and 2-ethoxyethanol, esters such as phthalic acid dialkyl ester , ketones such as acetone, cyclohexanone and isophorone, mineral oils such as machine oil, vegetable oils such as soybean oil and cotton seed oil, dimethylsulfoxide, N,N-dimethylformamide, acetonitrile, N-methylpyrrolidone water, and the like.
Examples of the surfactant utilized for emulsification, dispersing or spreading may include the following materials:anionic surfactants such as alkylsulfate ester salts, alkylsulfonate salts, alkylarylsulfonate salts, dialkyl sulfosuccinate salts and polyoxyethylenealkylaryl ether phosphate ester salts, nonionic surfactants such as polyoxyethylenealkyl ethers, polyoxyethylenealkylaryl ethers, polyoxyethylenepolyoxypropylene block copolymers, sorbitan fatty acid esters and polyoxyethylenesorbitan fatty acid esters; and the like.
Examples of the formulation auxiliary agents may include the following materials: ligninsulfonate salts, alginate salts, polyvinyl alcohol, gum arabic, CMC (carboxymethyl cellulose), PAP (acidic isopropylphosphate), and the like.
The present compounds are usually formulated and applied for the pre- or post-emergence soil, foliar, or flooding treatment of unfavorable weeds. The soil treatment may include soil surface treatment and soil incorporation treatment. The foliar treatments may include application over the plants and directed application in which a chemical is applied only to the unfavorable weeds so as to keep off the crops.
When the present compounds are used as active ingredients of herbicides, the application amount is usually in the range of 0.01 to 10,000 g, preferably 1 g to 8,000 g per hectare, although it may vary depending upon the weather conditions, formulation type, application timing, method of application, soil conditions, objective crop and objective unfavorable weed(s). In the case of emulsifiable concentrates, wettable powders, suspensible concentrates, concentrated emulsions, water dispersable granules, or the like, the formulation is usually applied at prescribed amounts after diluted with 10 L to 1,000 L of water (in which an adjuvant such as a spreading agent may be added, if necessary) per hectare. In the case of granules or certain types of suspensions, the formulation is usually applied as such without any dilution.
Example of the adjuvant used, if necessary, may include in addition to the surfactants described above, polyoxyethylene resin acids (esters), ligninsulfonate salts, abietate salts, dinaphthylmethanedisulfonate salts, crop oil concentrate, vegetable oils such as soybean oil, corn oil, cotton seed oil and sunflower oil.
The present compounds may be used in the places such as corn fields, wheat fields, barley fields, rice fields, sorghum fields, soybean fields, cotton fields, sugar beet fields, peanut fields, sunflower fields, rape fields and paddy fields.
The present compounds can also be utilized as active ingredients of harvest-aids such as desiccants and defoliants agents for cottons, desiccants of potatoes (Solanum tuberosum). In these cases, the present compounds are usually formulated in the same manner as the case where they are used as active ingredients of herbicides, and used alone or in combination with other harvesting aids for foliar treatment before the harvesting of crops.